Is there a method to "home bake" a lens profile?

DxO ViewPoint
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I have several “out of production” Minolta lenses. While I am not asking DxO to make profiles for all of them, is there a method of converting the (say) lensfun database info into something we can use while DxO develop proper profiles for more recent and still commercial lenses?

My particular area of interest is the Minolta 200/2.8 AF HS APO G I recently picked up on e-Bay. It’s a lovely lens, and I want to get the best out of it!

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Dear Mike,
I really like your idea.
An editor for lens correction would be very useful, and probably fun too!
I complete your demand with specific correction:
• Geometrical edition: sliders for barrel, pincushion, and moustache correction
• Color shift: on a green-magenta axis and a cyan-yellow axis, between the center and the edges
and the more classical corrections:
• Vignetting: same as Filmpack Elite
• Unsharp mask: with edge offset

It would be very useful for some old and rare lenses, but also for creative effects.
Maybe the best or funniest profiles can be shared in the dxo community.

A new feature for Filmpack or ViewPoint?
Kind regards,

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There is a request for something similar - see Option to manually select a lensprofile

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"A new feature for Filmpack or ViewPoint? "

ViewPoint, I hope, because I haven’t bought a license for Filmpack! But I see this as an essential (central) feature of PL. I came to PL from Bibble 5 Pro (I used to be a 100% Linux user), which has always had the ability to compensate for geometry and chromatic aberration. Sadly, when Corel got hold of it, the writing was on the wall, much as it now is for Sony A-Mount users.

I am afraid I don’t understand enough (actually, anything) about the operation of sharpening tools to see what you mean about the unsharp mask. I don’t do my sharpening in PL - if I can get a decent result with the Nik tools, fine. Otherwise Topaz AI.

Let’s hope the idea gets some traction in the user community and appeals to DxO - after all, if we users do even 40% of work for each lens adapter, we must save them a good deal of development time?

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Dear Mike,

“I am afraid I don’t understand enough (actually, anything) about the operation of sharpening tools”

For what I have understood, the “edge offset” slider allows to balance the sharpening effect from the center to the edge. It is a way to more sharpen the soft areas of the picture (usually the edges) than the center part, which is already naturally sharp. The result gives more homogeneity to the lens.

“after all, if we users do even 40% of work for each lens adapter, we must save them a good deal of development time?”

I do not believe that user’s profiles may be competitive with those of DxO, that stay on hundreds of scientific based pictures with calibrated tools and methods. But, with a comprehensive and usable lens profile’s editor, I hope a significant quality improvement for exotic lenses is reachable.

The need for “homemade profile editor” increases with the exponential possibilities of combinations between cameras and lenses, whatever their supplier. It would be also a smart response for the use of various adapters or rings.

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Absolument d’accord! Mais comme l’a dit qq1 d’autre, il faudrait d’abord que les matheux pensent comme des ingenieurs - qu’il ne fassent pas du bien l’ennemi du mieux!

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This should be doable since there’s a tool for creating your own lens profile for Lightroom available from Adobe.
Instructions (PDF)
More info (read the comments) and links to the Windows and Mac creator software.

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Tout à fait !

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Definitely need something like this for those odd lens that are not on the DXO to do list. These could be old and / or obscure lens or more modern lens - camera combinations using adapters that few would use and thus have limited market appeal.

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IIRC the Lensfun data are crop-related, rather than sensor-specific. But half a loaf is better than no bread, and a crust is too.

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An observation on this subject:

  • why did Adobe abandon “Adobe lens profile creator” which should - according to some - make DxO (Optics Pro at the time) totally obsolete?
    I think things are more complex than what we users think!
    Making a preset for an unsupported lens is possible, complicated but possible.
    I happened to do some for unsupported lenses. As long as it is a fixed focal length: for a zoom it is practically impossible.
    The distortion is relatively easy to correct: it is the same regardless of the diaphragm (f-stop).
    For vignetting, each opening must be analyzed and corrected. This means in theory one preset per opening (f-stop). in practice one can be satisfied with two or three corrections since the vignetting generally decreases while passing from f / 2.8 (for example) to f / 4 and then becomes negligible.
    Of course, you have to go read the exifs: there is no possibility of automatically choosing your preset accordingly. And if the Exifs are not present (not transmitted or nonexistent: old lens) it gets complicated … and I ignore the fact that some corrections are sensitive to the shooting distance!
    That being said, a preset, even a basic one where only distortion (approximately) and vignetting are corrected are a good starting point.
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I would have thought the EXIF was always present in a RAW - but what do I know, I only shoot Sony.
And for the rest, that’s what I meant by “half a loaf” and “crust”.

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I would say a main problem is variation in quality between the same lens. So testing one lens is not enough, you have to test multiple. And most users will only have access to one. So your profile would only work for your own lens, and not necessarily for others. Never mind not a bad idea to support this, but I guess complicated and very niche.

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As I understand the Lensfun database, their measurements are derived from more than one copy of the lenses - though I have to say I have never been part of their project. But as I said, a crust may be only a crust, but it is better than nobread at all.

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You seem to really like bread! :wink:

If this is true, I recommend that you read the books by Steven Lawrence Kaplan. He is an American university professor specializing in the history of bread and baking. He is very famous in France.
His books are a treat for foodies and really exciting.

Kind regards,

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I suggested that over a year ago in the section “Which feature do you need?” with zero user interest and no DxO comments:

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Je ne connais pas la version francaise. Mais l’on pourrait bien dire “Un bon ‘tiens!’ vaut deux ‘tu l’auras’”. Et encore DxO ne dit pas que nous l’aurons …

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Thanks for the link to the tutorial. About your former proposal, the subject is nearly the same, but this one brings a new approach:

• The profile’s editor would be part of ViewPoint. ViewPoint has no longer improvements, and its interest (as an independent application) decreases with the new version of the Nik Collection.

• The profile’s editor would be also used in a creative purpose, not only to fix optical issues. For example, fisheye/de-fisheye, let or increase the distortion only on the edge… It is the reason why this feature is more appropriate to ViewPoint than to DPL.

• The profile’s editor should be able to fix more complex optics defects than those DPL can do with only the manual corrections, like moustache distortion, color shift, left-right inhomogeneity (centering defect), and maybe others.

• As an independent application, it could be applied on various kind of files, included the DNGs that are not recognized by DPL (e.g. DNG from smartphones).

• Into DPL, exifs data could be automatically read to propose the proper set of customized profiles, or to let selecting one in a library.

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Just being able to save manual lens corrections as a named profile would be a good start.

PS. Cluttering presets with this for each custom lens would not be an efficient solution.

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I dunno Alec. I only have half a dozen unsupported lenses. It’s true that some of them are zooms, so I might need to save more than one preset x lens; but even if that turned out to be the case, it still looks more attractive than having to remember the same number of corrections (not to mention the order in which to apply them).
All the same, in the interests of saving labour, I would like DxO to find a way of making this more automagical.